Touch sensible organic light emitting device

ABSTRACT

Embodiments of the present invention generally relate to a touch sensible organic light emitting device. The organic light emitting device according to an exemplary embodiment of the present invention comprises: a substrate; a thin film transistor disposed on the substrate; an organic light emitting element connected to the thin film transistor and receiving a data voltage; a plurality of encapsulation thin films disposed on the organic light emitting element, and encapsulating the thin film transistor and the organic light emitting element; a planarization layer disposed on the encapsulation thin film; and a touch sensor disposed on the planarization layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/479,090 filed Apr. 4, 2017, which is a continuation of U.S. patentapplication Ser. No. 15/071,137, filed Mar. 15, 2016, which is acontinuation application of U.S. patent application Ser. No. 12/421,641filed on Apr. 10, 2009, which claims priority to and the benefit ofKorean Patent Application No. 10-2008-0120015 filed in the KoreanIntellectual Property Office on Nov. 28, 2008, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND (a) Technical Field

Embodiments of the present invention generally relate to a touchsensible organic light emitting device.

(b) Description of the Related Art

An organic light emitting device includes two electrodes and an organiclight emitting layer interposed between the two electrodes. One of thetwo electrodes injects holes and the other injects electrons into thelight emitting layer. The injected electrons and holes combine to formexcitons and the excitons emit light as discharging energy.

An organic light emitting device includes an organic light emittingelement and a plurality of thin film transistors for driving it. Thethin film transistors comprise a plurality of thin films and aregenerally disposed at the lower side of the organic light emittingdevice, the organic light emitting element is disposed at the upper sidethereof, and an anode of the organic light emitting element is disposedat the lower side and a cathode thereof is disposed at the upper side.

An organic light emitting element includes an anode and a cathode as twoelectrodes, and an organic light emitting member as the emission layerdisposed therebetween. An organic light emitting member emits light ofthree primary colors such as red, green, and blue, or white. Materialsfor the organic light emitting member vary according to the colors thatthe organic light emitting member emits. When an organic light emittingmember emits white light, light emitting materials that emit red, green,and blue are stacked so that the synthesized light becomes white.Moreover, in the case where the organic light emitting member emits thewhite light, color filters may be added to obtain light of a desiredcolor.

Meanwhile, thin film transistors include a switching transistor forswitching a voltage applied to each pixel, and a driving transistor fordriving the organic light emitting element.

An organic light emitting device may be classified into a top emissiontype that emits light in the upper direction and a bottom emission typethat emits light in the lower direction.

On the other hand, a touch screen panel is a device for allowing amachine such as a computer to perform a desired command by writing acharacter, drawing a picture, or executing an icon through touching afinger or a touch pen (or a stylus) on a screen. A display device towhich a touch screen panel is attached can determine whether a userfinger or a touch pen, etc., touches a screen and touch positioninformation. The cost of such a display device, however, increases dueto the touch screen panel. Because of additional processes for adheringor coupling the touch screen panel to the display panel, the yield ofthe organic light emitting device is reduced, the luminance and theviewing angle of the display panel are deteriorated, and the overallthickness of the product increases.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the disclosure andtherefore it may contain information that does not form the prior artthat is already known in this country to a person of ordinary skill inthe art.

SUMMARY

An organic light emitting device according to an exemplary embodiment ofthe present invention comprises: a substrate; a thin film transistordisposed on the substrate; an organic light emitting element connectedto the thin film transistor and receiving a data voltage; a plurality ofencapsulation thin films disposed on the organic light emitting element,and encapsulating the thin film transistor and the organic lightemitting element; a planarization layer disposed on the encapsulationthin film; and a touch sensor disposed on the planarization layer.

The plurality of encapsulation thin films may comprise an organicinsulator or an inorganic insulator.

The inorganic insulator may comprise silicon oxide or silicon nitride.

The planarization layer may comprise an organic material, and has a flatsurface.

The touch sensor may comprise a variable capacitor connected to asensing signal line transmitting a sensing signal, and a referencecapacitor connected between the sensing signal line and a referencevoltage terminal.

A capacitance of the variable capacitor may be changed according to anexternal touch comprising a pressure applied to one terminal of thevariable capacitor.

The touch sensor may comprise a first transparent conductive layer.

The first transparent conductive layer may comprise indium tin oxide(ITO) or indium zinc oxide (IZO).

A plurality of electrode island portions each disposed on a corner ofthe substrate and transmitting a voltage to the first transparentconductive layer may be further comprised.

A signal line pattern connecting the plurality of electrode islandportions; and a sensing signal processor connected to the signal linepattern and receiving the changed voltage according to a touch on thefirst transparent conductive layer and generating a digital sensingsignal may be further comprised.

A plurality of electrode island portions each disposed on a corner ofthe substrate and transmitting a high-frequency signal to the firsttransparent conductive layer, a signal line pattern connecting theplurality of electrode island portions, and a sensing signal processorconnected to the signal line pattern and receiving a changedhigh-frequency signal according to a touch on the first transparentconductive layer and generating a sensing signal may be furthercomprised.

The touch sensor may further comprise a first insulating layer disposedon the first transparent conductive layer; and a second transparentconductive layer disposed on the first insulating layer.

A plurality of electrode island portions each disposed on a corner ofthe substrate and transmitting a voltage to the first and secondtransparent conductive layers, a signal line pattern connecting theplurality of electrode island portions, and a sensing signal processorconnected to the signal line pattern and receiving a changed voltageaccording to a touch on the second transparent conductive layer andgenerating a sensing signal may be further comprised.

A plurality of electrode island portions each disposed on a corner ofthe substrate and transmitting a high-frequency signal to the first andsecond transparent conductive layers, a signal line pattern connectingthe plurality of electrode island portions, and a sensing signalprocessor connected to the signal line pattern and receiving a changedhigh-frequency signal according to a touch on the second transparentconductive layer and generating a sensing signal may be furthercomprised.

A second insulating layer disposed on the second transparent conductivelayer may be further comprised.

The first transparent conductive layer may be connected to the referencevoltage terminal, and the second transparent conductive layer isconnected to a sensing signal line disposed on the substrate.

A sensing signal processor receiving a changed voltage of the secondtransparent conductive layer according to a touch on the secondinsulating layer and generating a sensing signal may be furthercomprised.

The organic light emitting element may comprise a pixel electrodeconnected to the thin film transistor and receiving a data voltagethrough the thin film transistor, an organic light emitting memberdisposed on the pixel electrode, and a common electrode disposed on theorganic light emitting member.

The thin film transistor may comprise a switching transistor controlledby a scanning signal; and a driving transistor connected to theswitching transistor and transmitting an output current to the organiclight emitting element.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a touch sensible organic light emittingdevice according to an exemplary embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram of a touch sensible organiclight emitting device according to an exemplary embodiment of thepresent invention.

FIG. 3 is a cross-sectional view of one pixel of a touch sensibleorganic light emitting device according to an exemplary embodiment ofthe present invention.

FIG. 4 is an equivalent circuit diagram of a touch sensor of a touchsensible organic light emitting device according to an exemplaryembodiment of the present invention.

FIG. 5 and FIG. 6 are cross-sectional views of one pixel of a touchsensible organic light emitting device according to an exemplaryembodiment of the present invention.

FIG. 7 is a view showing a connection relationship of a high-frequencysensor in a touch sensible organic light emitting device according to anexemplary embodiment of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention will be described more fullyhereinafter with reference to the accompanying drawings, in whichexemplary embodiments of the invention are shown. As those skilled inthe art would realize, the described embodiments may be modified invarious different ways, all without departing from the spirit or scopeof the present disclosure.

In the drawings, the thickness of layers, films, panels, regions, etc.,are exaggerated for clarity. Like reference numerals designate likeelements throughout the specification. It will be understood that whenan element such as a layer, film, region, or substrate is referred to asbeing “on” another element, it may be directly on the other element, orintervening elements may also be present. In contrast, when an elementis referred to as being “directly on” another element, there are nointervening elements present.

A touch sensible organic light emitting device according to an exemplaryembodiment of the present invention will now be described with referenceto FIGS. 1 and 2.

FIG. 1 is a block diagram of a touch sensible organic light emittingdevice according to an exemplary embodiment of the present invention,and FIG. 2 is an equivalent circuit diagram of a touch sensible organiclight emitting device according to an exemplary embodiment of thepresent invention.

Referring to FIG. 1, an organic light emitting device according to anexemplary embodiment of the present invention includes a display panel300 including a touch sensor (not shown), a scan driver 400, a datadriver 500 and a sensing signal processor 800 that are connected to thedisplay panel 300, and a touch determining unit 900 connected to thesensing signal processor 800.

Referring to FIG. 1 and FIG. 2, an organic light emitting deviceaccording to the present exemplary embodiment includes a plurality ofsignal lines 121, 171, and 172, and a plurality of pixels PX connectedthereto and arranged substantially in a matrix.

The signal lines include a plurality of scanning signal lines 121 fortransmitting gate signals (or scanning signals), a plurality of datalines 171 for transmitting data signals, and a plurality of drivingvoltage lines 172 for transmitting a driving voltage. The scanningsignal lines 121 extend substantially in a row direction and aresubstantially parallel to each other, and the data lines 171 extendsubstantially in a column direction and are substantially parallel toeach other. Although the driving voltage lines 172 are shown asextending substantially in a column direction, the driving voltage lines172 may extend in a row direction or in a column direction, or may beformed in a matrix. Also, the signal lines may further comprise asensing signal line (not shown) for transmitting a sensing signal of thetouch sensor.

As shown in FIG. 2, each pixel PX includes a switching transistor Qs, adriving transistor Qd, a storage capacitor Cst, and an organic lightemitting element LD.

The switching transistor Qs includes a control terminal, an inputterminal, and an output terminal, in which the control terminal isconnected to the scanning signal line 121, the input terminal isconnected to the data line 171, and the output terminal is connected tothe driving transistor Qd. The switching transistor Qs transmits a datasignal received from the data line 171 to the driving transistor Qd inresponse to the scanning signal received from the scanning signal line121.

The driving transistor Qd also includes a control terminal, an inputterminal, and an output terminal, in which the control terminal isconnected to the switching transistor Qs, the input terminal isconnected to the driving voltage line 172, and the output terminal isconnected to the organic light emitting element LD. The drivingtransistor Qd transmits an output current I_(LD) of which the magnitudevaries according to the voltage applied between the control terminal andthe output terminal of the driving transistor Qd.

The capacitor Cst is connected between the control terminal and theinput terminal of the driving transistor Qd. The capacitor Cst storesthe data signal applied to the control terminal of the drivingtransistor Qd and maintains the stored data signal even after theswitching transistor Qs is turned off.

The organic light emitting element LD may be an organic light emittingdiode (OLED), for example having an anode connected to the outputterminal of the driving transistor Qd and a cathode connected to acommon voltage Vss. The organic light emitting element LD emits light ofwhich the intensity is varied according to the output current I_(LD) ofthe driving transistor Qd, to display an image. The organic lightemitting element LD may include an organic material uniquely emitting atleast one of the primary colors such as red, green, or blue, or a whitecolor, and the organic light emitting device emits desired images by aspatial sum thereof.

The switching transistor Qs and the driving transistor Qd may ben-channel field effect transistors (FET); however, at least one of theswitching transistor Qs and the driving transistor Qd may be a p-channelFET. Moreover, the connection relationship among the transistors Qs andQd, the storage capacitor Cst, and the organic light emitting element LDmay be changed.

Referring again to FIG. 1 and FIG. 2, the scan driver 400 is connectedto the scanning lines 121, and applies scanning signals that are acombination of a high voltage Von for turning on the switchingtransistors Qs and a low voltage Voff for turning off the switchingtransistors Qs to the scanning lines 121.

The data driver 500 is connected to the data lines 171 in the displaypanel 300 and applies data voltages to the data lines 171.

The sensing signal processor 800 receives a sensing signal from thetouch sensor (not shown) of the display panel 300, performs a signalprocess such as amplifying and filtering, and converts the processedsignal to a digital sensing signal DS through an analog-digitalconversion.

The touch determining unit 900 receives the digital sensing signal DSfrom the sensing signal processor 800, performs a predeterminedcalculation process, and determines whether the display panel 300 istouched or not as well as a touch position to generate a touchinformation INF, and then, outputs the touch information INF to anexternal device. An external device may transmit the image signal basedon the touch information INF to the organic light emitting device.Alternatively, when the external device directly receives the digitalsensing signal DS and performs the function of the touch determiningunit 900 such as determining the touch position, the touch determiningunit 900 may be omitted.

Next, a display operation of the organic light emitting device will bedescribed according to one or more embodiments.

The data driver 500 receives digital output image signals for a row ofpixels PX, and converts the digital output image signals into analogdata voltages to apply to the data lines 171.

The scan driver 400 applies the high voltage Von to the gate lines 121to turn on the switching element Qs coupled to the gate lines 121.Thereby, the data voltage applied to the data lines 171 is applied tothe corresponding pixel PX through the turned on switching element Qs.

The driving transistor Qd receives the data voltages through the turnedon switching element Qs thereby generating a corresponding outputcurrent I_(LD). The organic light emitting element LD emits light havingan intensity corresponding to the output current I_(LD) of the drivingtransistor Qd.

By repeating the above procedure by a unit of one horizontal period,which is denoted by “1H”, the scanning signal is sequentially appliedfor all scanning signal lines 121 and the data voltage is applied to allpixels PX to display an image of one frame.

Next, the display panel of the organic light emitting device shown inFIG. 1 and FIG. 2 will be described in detail according to one or moreembodiments with reference to FIG. 3 and FIG. 4 as well as FIG. 1 andFIG. 2.

FIG. 3 is a cross-sectional view of one pixel of a touch sensibleorganic light emitting device according to an exemplary embodiment ofthe present invention, and FIG. 4 is an equivalent circuit diagram of atouch sensor of a touch sensible organic light emitting device accordingto an exemplary embodiment of the present invention,

Referring to FIG. 4, a touch sensor of a touch sensible organic lightemitting device according to an exemplary embodiment of the presentinvention includes a variable capacitor Cv connected to the sensingsignal line SL, and a reference capacitor Cr connected between thesensing signal line SL and the reference voltage Vr terminal.

The capacitance of the variable capacitor Cv may be varied according toan external touch applied to the upper terminal of the variablecapacitor Cv such as a contact (touch) of a finger Fn of a user. Forexample, the external touch may be a pressure. If the capacitance of thevariable capacitor Cv is changed, the node voltage Vn between of thereference capacitor Cr and the variable capacitor Cv depending on thecapacitance changes. The node voltage Vn is transmitted through thesensing signal line SL as a sensing signal, and either the existence orlack of a touch as well as a touch position may be determined based onthe sensing signal. Here, the reference capacitor Cr has a fixedcapacitance and the reference voltage Vr applied to the referencecapacitor Cr has a uniform voltage, such that the node voltage Vn ischanged within a predetermined range. Accordingly, the sensing signalmay always have a voltage level within a predetermined range such thatthe existence or lack of a touch as well as touch position may be easilydetermined.

Next, a cross-sectional structure of the driving transistor Qd, theorganic light emitting element LD, and the touch sensor of a touchsensible organic light emitting device according to an exemplaryembodiment of the present invention will be described with reference toFIG. 3, FIG. 1, FIG. 2, and FIG. 4.

A plurality of gate conductors including control electrodes 124 areformed on an insulation substrate 110 made of transparent glass orplastic.

A gate insulating layer 140 that may be made of silicon nitride (SiNx)or silicon oxide (SiOx) is formed on the gate conductor.

A plurality of semiconductors 154 are formed on the gate insulatinglayer 140. The semiconductors 154 overlap the control electrodes 124.

A plurality of pairs of ohmic contacts 163 and 165 are formed on thesemiconductors 154.

A plurality of data conductors including a plurality of driving voltagelines 172 and a plurality of output electrodes 175 are formed on theohmic contacts 163 and the gate insulating layer 140.

The driving voltage lines 172 transmit a driving voltage, and includeinput electrodes 173 extending toward the control electrodes 124.

The output electrodes 175 are separated form the driving voltage lines172.

The input electrodes 173 and the output electrodes 175 oppose each otheron the semiconductors 154.

A control electrode 124, an input electrode 173, and an output electrode175 form a driving transistor Qd along with a semiconductor 154, and achannel of the driving transistor Qd is formed in the semiconductor 154between the input electrode 173 and the output electrode 175.

The ohmic contacts 163 and 165 are only disposed between the underlyingsemiconductor 154 and the overlying data conductor, thereby reducing thecontact resistance therebetween. The semiconductor 154 has a portionthat is exposed without being covered with the input electrode 173 andthe output electrode 175, and a portion between the source electrodes173 and the drain electrodes.

A lower passivation layer 180 p made of an inorganic insulator such assilicon nitride or silicon oxide is formed on the gate insulating layer140, the data conductor, and the exposed semiconductor 154.

An upper passivation layer 180 q is formed on the lower passivationlayer 180 p. The upper passivation layer 180 q may be made of an organicmaterial, and may have a flat surface.

The lower passivation layer 180 p and the upper passivation layer 180 qhave contact holes 185 exposing the output electrodes 175.

A plurality of pixel electrodes 191 are formed on the upper passivationlayer 180 q. The pixel electrodes 191 may be made of a reflective metalsuch as Al, Ag, Au, Pt, Ni, Cu, W, or alloys thereof. The pixelelectrodes 191 may further include a transparent electrode that isdisposed on or under the reflective metal and made of a conductive metaloxide such as indium tin oxide (ITO) or indium zinc oxide (IZO). Thetransparent electrode may improve the cohesion between the layer made ofa reflective metal and another layer, and may prevent corrosion thereof.

The pixel electrodes 191 are physically-electrically connected to theoutput electrodes 175 through the contact holes 185.

Partitions 360 are formed on the upper passivation layer 180. Thepartitions 360 define a plurality of openings enclosing edges of thepixel electrodes 191 like a bank, and may be made of an organicinsulator or an inorganic insulator. Alternatively, the partitions 360may be made of a photoresist including black pigments, and in this case,the partitions 360 may function as a light blocking member, therebysimplifying the manufacturing process.

An organic light emitting member 370 is formed in openings defined bythe partitions 360 on the pixel electrodes 191. The organic lightemitting member 370 may be made of an organic material uniquely emittinglight of one primary color such as red, green, or blue. The organiclight emitting device displays a desired image by spatially combiningprimary colors of the organic light emitting members 370.

The organic light emitting member 370 may have a multi-layer structureincluding auxiliary layers for improving light emitting efficiency of anemission layer (not shown) in addition to the emission layer. Anauxiliary layer may include an electron transport layer (not shown) anda hole transport layer (not shown) that achieve a balance of electronsand holes, and an electron injection layer (not shown) and a holeinjection layer (not shown) that reinforce the injection of theelectrons and the holes.

A common electrode 270 is formed on the organic light emitting member370. The common electrode 270 receives a common voltage Vss, and may bemade of a transparent conductive material such as ITO or IZO, etc., orof a thin metal layer through which light may be transmitted.

In the organic light emitting device, a pixel electrode 191, an organiclight emitting member 370, and the common electrode 270 form an organiclight emitting element LD having the pixel electrode 191 as an anode andthe common electrode 270 as a cathode, or vice versa. The organic lightemitting device display emits light in the upper direction with respectto the substrate 110 to display images.

An encapsulation thin film layer 260 including a first encapsulationthin film 261, a second encapsulation thin film 262, and a thirdencapsulation thin film 263 is formed on the common electrode 270. Thefirst, second, and third encapsulation thin films 261, 262, and 263 maybe made of an inorganic material such as silicon oxide or siliconnitride, or of an organic insulator. The encapsulation layerencapsulates the organic light emitting member 370 and the commonelectrode 270 such that moisture and/or oxygen from the exterior may beprevented from flowing into them and oxidation of the organic lightemitting member 370 and the common electrode 270 may be prevented. Thethird encapsulation thin film 263 that is disposed uppermost maycompletely encapsulate the organic light emitting member 370 and thecommon electrode 270 by covering the upper surface of the substrate 110at the edges of the display panel 300. Accordingly, the thin films areused to encapsulate and protect the organic light emitting member 370and so forth such that the thickness of the organic light emittingdevice may be further reduced and the display characteristics such astransmittance and viewing angle may be improved.

According to another exemplary embodiment of the present invention, theencapsulation thin film layer 260 may be made of a single layer, doublelayers, or a plurality of layers of more than two layers includinginorganic insulators or organic insulators.

A planarization layer 240 is formed on the encapsulation thin film layer260. The planarization layer 240 may be made of an organic material, andflatten the surface on the encapsulation thin film layer 260.

A lower transparent conductive layer 232, an insulating layer 220, andan upper transparent conductive layer 231 may be sequentially formed onthe whole surface of the planarization layer 240.

The lower and upper transparent conductive layers 232 and 231 may bemade of a transparent conductive material such as ITO, ATO (antimony tinoxide), or IZO. The lower transparent conductive layer 232 may receive apredetermined voltage such as the reference voltage Vr, and the uppertransparent conductive layer 231 may be connected to the sensing signalline SL.

The insulating layer 220 may be made of an inorganic material such assilicon oxide or silicon nitride, or of an organic insulator through,for example, spin coating or printing.

The lower transparent conductive layer 232 and the upper transparentconductive layer 231 form a reference capacitor Cr along with theinsulating layer 220.

A surface insulating layer 210 that may be made of an inorganic materialsuch as silicon oxide or silicon nitride, or an organic insulator, iscoated on the whole surface of the upper transparent conductive layer231. The upper surface of the surface insulating layer 210 or anexternal touch object form the variable capacitor Cv along with theupper transparent conductive layer 231, wherein the surface insulatinglayer 210 between the upper surface of the surface insulating layer 210or the external touch object, and the upper transparent conductive layer231 functions as a dielectric material of the variable capacitor Cv.

Referring to FIG. 3 and FIG. 4, when an external touch by a finger Fn isapplied to any portion on the surface insulating layer 210, the voltageof the upper transparent conductive layer 231, that is, the node voltageVn between the reference capacitor Cr and the variable capacitor Cv ischanged. Alternatively, the capacitance of the variable capacitor Cvchanges at the touch portion such that the node voltage Vn of the uppertransparent conductive layer 231 may be changed. For example, if apressure by a touch is applied to the surface insulating layer 210, thethickness of the surface insulating layer 210 is changed so that thecapacitance of the variable capacitor Cv may be changed. Thus, the nodevoltage Vn of the upper transparent conductive layer 231 depending onthe capacitance of the variable capacitor Cv is changed. The changednode voltage Vn of the upper transparent conductive layer 231 istransmitted through the sensing signal line SL as a sensing signal, andeither a touch or a lack of touch may be determined based on the sensingsignal. Such sensing operation is separately executed from theabove-described display operation, and may not be influenced by thedisplay operation or vice versa.

According to another embodiment, a conductive layer (not shown) may befurther formed on the surface insulating layer 210. Also, a coatinglayer (not shown) for protection of the upper transparent conductivelayer 231 and reduction of noises may be further formed on the surfaceinsulating layer 210.

Next, a touch sensible organic light emitting device according toanother exemplary embodiment of the present invention will be describedwith reference to FIG. 5 to FIG. 7 as well as FIG. 1 and FIG. 2.

FIG. 5 and FIG. 6 are cross-sectional views of one pixel of a touchsensible organic light emitting device according to an exemplaryembodiment of the present invention, and FIG. 7 is a view showing aconnection relationship of a high-frequency sensor in a touch sensibleorganic light emitting device according to an exemplary embodiment ofthe present invention.

Referring to FIG. 5 and FIG. 6, a touch sensible organic light emittingdevice according to an exemplary embodiment of the present invention hasalmost the same cross-sectional structure as the organic light emittingdevice shown in the embodiment of FIG. 3. In the present exemplaryembodiment, descriptions of the same elements will be omitted, and thesame constituent elements as in the above-described exemplary embodimentare indicated by the same reference numerals.

Referring to FIG. 5, a gate conductor including a control electrode 124,a gate insulating layer 140, a plurality of semiconductors 154, aplurality of pairs of ohmic contacts 163 and 165, a plurality of dataconductors including a driving voltage line 172 and an output electrode175, a lower passivation layer 180 p and an upper passivation layer 180q, a plurality of pixel electrodes 191, a partition 360, an organiclight emitting member 370, a common electrode 270, an encapsulation thinfilm layer 260 including a first encapsulation thin film 261, a secondencapsulation thin film 262, and a third encapsulation thin film 263, aplanarization layer 240, and a transparent conductive layer 232 a aresequentially formed on the insulation substrate 110.

Referring to FIG. 1 and FIG. 7, a plurality of electrode island portions233 are formed at the four corners of the display panel 300 in theorganic light emitting device according to the present exemplaryembodiment. The electrode island portions 233 are connected to the fourcorners of the transparent conductive layer 232 a. The electrode mayinclude electrode islands (not shown) for transmitting a high-frequencysignal or a predetermined voltage to the transparent conductive layer232 a and a signal receiver (not shown) for sensing a changedhigh-frequency signal or voltage.

A signal line pattern 80 that may have a stripe shape and that may bemade of a metal such as silver or aluminum is formed near the edge ofthe display panel 300. The signal line pattern 80 connects fourelectrode island portions 233, and the end portion thereof is connectedto the sensing signal processor 800. The signal line pattern 80 may beformed on the transparent conductive layer 232 a.

In such an organic light emitting device, a high-frequency signal or avoltage is applied to the transparent conductive layer 232 a through theelectrode islands (not shown) of the electrode island portions 233. Ifan external object such as a finger Fn touches the transparentconductive layer 232 a, the high-frequency signal is changed or thevoltage is changed, and the changed signal such as the changedhigh-frequency signal is detected by the signal receiver (not shown) ofthe electrode island portions 233. The detected signal is input to thesensing signal processor 800 and the touch determining unit 900 throughthe signal line pattern 80, thereby determining the touch position.

Also, referring to FIG. 6, in a touch sensible organic light emittingdevice according to another exemplary embodiment of the presentinvention, a lower transparent conductive layer 232 may be formed inreplacement of the transparent conductive layer 232 a of the organiclight emitting device shown in the embodiment of FIG. 5. Also, aninsulating layer 220, an upper transparent conductive layer 231 and acoating layer 215 may be further formed on the lower transparentconductive layer 232. The coating layer 215 may protect the uppertransparent conductive layer 231 from contamination and externalinfluence.

Referring to FIG. 6 and FIG. 7, the lower transparent conductive layer232 and the upper transparent conductive layer 231 are connected to theelectrode islands (not shown) of the electrode island portions 233,thereby receiving the high-frequency signal or the predeterminedvoltage. A changed high-frequency signal or a changed voltage by a touchis detected by the signal receiver (not shown) of the electrode islandportions 233. Also, many characteristics of the organic light emittingdevice shown in the embodiments of FIG. 5 and FIG. 7 may be applied tothe organic light emitting display device shown in the embodiments ofFIG. 6 and FIG. 7.

Numerous characteristics of the touch sensible organic light emittingdevice shown in the embodiment of FIG. 3 may be applied identically tothe organic light emitting device shown in the embodiments of FIG. 5 toFIG. 6.

The sensing method of an organic light emitting device according to anexemplary embodiment of the present invention is an example of a touchsensing method. A touch sensor operating by various sensing methods suchas the capacitance type sensing method may be included.

According to an exemplary embodiment of the present invention, organiclight emitting elements and thin film transistors of an organic lightemitting device may be encapsulated by several encapsulation thin films,and a touch sensor of the capacitance type sensing method that is thinmay be formed. Accordingly, the thickness of the touch sensible organiclight emitting device may be reduced, and the display characteristicssuch as transmittance and viewing angles may be improved.

Embodiments of the present invention may be applied to an organic lightemitting device having various structures.

While this disclosure has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the disclosure is not limited to the disclosedembodiments, but, on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A light emitting display device, comprising: asubstrate; a thin film transistor disposed on a surface of thesubstrate; a passivation layer covering the thin film transistor; afirst electrode on the passivation layer, the first electrode beingconnected to the thin film transistor through a via in the passivationlayer; a partition comprising an opening exposing a portion of the firstelectrode; a second electrode overlapping the portion of the firstelectrode; a light emitting layer comprising a portion in the opening,the portion of the light emitting layer being between the portion of thefirst electrode and the second electrode; a plurality of insulatinglayers on the second electrode; and a touch sensing electrodeoverlapping the second electrode, the plurality of insulating layersbeing between the touch sensing electrode and the second electrode,wherein the plurality of insulating layers comprises: a first layer onthe second electrode, an organic planarization layer on the secondelectrode, the first layer being between the organic planarization layerand the second electrode; and a pair of inorganic layers on the secondelectrode, wherein the pair of inorganic layers comprises: a firstinorganic layer contacting the first layer; and a second inorganic layercontacting the organic planarization layer, the second inorganic layercontacting the first inorganic layer in a region overlapping thepassivation layer, and wherein the region overlaps the passivation layerin a direction normal to the surface of the substrate.
 2. The lightemitting display device of claim 1, wherein: the first inorganic layercomprises a depression overlapping the portion of the first electrode inthe direction; and the organic planarization layer comprises a planarsurface overlapping the depression in the direction.
 3. The lightemitting display device of claim 1, wherein the first layer comprises aninorganic material.
 4. The light emitting display device of claim 1,further comprising: a first insulating layer between the touch sensingelectrode and the plurality of insulating layers.
 5. The light emittingdisplay device of claim 4, wherein: the touch sensing electrode is amonga plurality of touch sensing electrodes; and the first insulating layerseparates some of the plurality of touch sensing electrodes from oneanother.
 6. The light emitting display device of claim 4, furthercomprising: a second insulating layer on the first insulating layer,wherein the touch sensing electrode is between the second insulatinglayer and the first insulating layer.
 7. The light emitting displaydevice of claim 6, further comprising: a protection layer on the secondinsulating layer, wherein the second insulating layer is between theprotection layer and the touch sensing electrode.
 8. The light emittingdisplay device of claim 1, wherein: the first inorganic layer comprises:a first portion overlapping the opening in the direction; and a secondportion overlapping the partition in the direction; and the firstportion is closer to the substrate than the second portion.
 9. Anapparatus comprising: a display panel; and a touch sensor on the displaypanel, wherein the display panel comprises: a substrate; a thin filmtransistor on a surface of the substrate; a passivation layer coveringthe thin film transistor; a pixel electrode electrically connected tothe thin film transistor via a hole in the passivation layer; apartition comprising an opening exposing a surface of the pixelelectrode; a common electrode overlapping the surface of the pixelelectrode; an electroluminescent layer comprising a portion between thesurface of the pixel electrode and the common electrode; and a pluralityof insulating layers on the common electrode, wherein the touch sensorcomprises a touch sensing electrode, the plurality of insulating layersbeing between the touch sensing electrode and the common electrode,wherein the plurality of insulating layers comprises: an organic layeron the common electrode; a first layer between the organic layer and thecommon electrode; a first inorganic layer between the first layer andthe organic layer, the first inorganic layer touching the first layer;and a second inorganic layer between the touch sensing electrode and thefirst inorganic layer, the second inorganic layer touching the firstinorganic layer in a region overlapping the passivation layer in adirection normal to the surface of the substrate, and wherein theorganic layer comprises: a first surface facing the first inorganiclayer; and a second surface opposing the first surface, the secondsurface being more planar than the first surface.
 10. Theelectroluminescent display device of claim 9, wherein the touch sensingelectrode forms a layer grown directly on a surface of the displaypanel.